Cole-Cole Model for the Dielectric Characterization of Healthy Skin and Basal Cell Carcinoma at THz Frequencies

• Published in: IEEE open journal of engineering in medicine and biology Vol. 5; pp. 600 - 606
• Main Authors: Mattana, Enrico, Lodi, Matteo Bruno, Simone, Marco, Mazzarella, Giuseppe, Fanti, Alessandro
• Format: Journal Article
• Language: English
• Published: United States IEEE 2024; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Basal cell carcinoma; Basal cell carcinoma (BCC); Biological system modeling; cole-cole model; dielectric; Dielectrics; Dispersion; double Debye model; Errors; Genetic algorithms; Least squares method; Moisture content; Multipoles; Permittivity; Skin; Skin cancer; terahertz; Terahertz communications; Terahertz radiation; Tissues; Water content; Basal cell carcinoma (BCC); double Debye model; terahertz; cole-cole model; dielectric
• ISSN: 2644-1276; 2644-1276
• DOI: 10.1109/OJEMB.2024.3438562

THz radiationeffectively probes biological tissue water content due to its high sensibility to polar molecules. Skin and basal cell carcinoma (BCC), both rich in water, have been extensively studied in the THz range. Typically, the Double Debye model is used to study their dielectric permittivity. This work focuses on the viability of the multipole Cole-Cole model as an alternative dielectric model. To determine the best fit parameters, we used a genetic algorithm-based approach, solving a least squares problem. Compared with the Double Debye model, a maximum reduction of the RMSE value up to more than 50% and maximum relative percentage errors of 2.8% have been measured for both second and third order Cole-Cole models. Since the errors of the second and third order Cole-Cole models are similar, a two-poles model is enough to describe the behaviour both tissues from 0.2 THz to 2 THz.